The Cat's EXI Goes Down AND BACK AGAIN!

[BTCat]

I finally had a crash due to mechanical failure and I ripped the EXI up pretty badly on battery #4 today. I was at a hover at about 10 ft. I gunned it and gave it hard right stick forward elevator and a little rudder. I like the way that thing swings hard right and rockets up and across. I had been doing that all evening. The thing went nuts, rolled and went to the ground. I tried to correct, and then just killed the throttle. Couldn't figure out WTF .

I looked at the carnage when I got home and the boom was very loose on the boom block. The wires I had to my CP2 where twisted around the boom an extra turn or two. So, do you know what happens when the boom twists and your CP2 sensors are hooked to it, especially the vertical sensor? Not to mention the gyro. Dam thing goes nuts. There wasn't enough altitude to allow me more than a half second to observe, and I now know there would have been no way to correct, but I would assume if I had had it about 50 ft up I would have gotten one helluva show while the two CP2 sensors tired to make the heli go up when up was actually down, -- er, over -- er under er WTF I'll bet it would have been a great video, especially adding the gyro in the mix.

The boom was tight when I started flying. I always check the boom, the tail and the belt. But the EXI boom block I was using has a little brass dowel pin that indexes with the boom. That thing was worked back all the way into its hole. I'm pretty sure that was the primary cause of the crash.

So far, I have three stripped servos, boom, boom supports, rudder control rod, tail fins, bottom frame tray (broke the skids right off), blades, almost every linkage an no telling what else. Looks like warmed over doggy dodo, but it doesn't look too expensive.

And I'm still in a good mood!! What's up with that

I'll try to post pictures later.

[akent]

Your mood is awesome, BT!

Ya gotta love a really sweet heli smackaroo every now and then!
I'm way overdue with my 450. I have flown it maybe 25 batteries since the last smackaroo.
The 500 hasn't seen the bottom of a gopher hole in probably the same number of batteries.
The ES600 is the last heli to be rolled up in a ball. That thing is still not right...
Kent

[BTCat]

Well, Kent, the differance between this one and the last one is that I was having a helluva time and flying very well. And FAST. Dam I was finally flying as fast as that thing could go side-in and pretty fast in the turns. LOVED IT! Only let the CP2 save me once. Almost ready to set up Idle Up...Almost ;D

[akent]

That's awesome flying BT!!
I'm really impressed to hear about how well the CP2 works. I've read about Mckrackin and a couple of others rave about them. It's an amazing piece of equipment.

Once I get the vibes out of my ES600, I may get one of those for it. I would like to build up a camera platform.

Take care,
Kent

[BTCat]

Sept 6, 2009 15:08:24 GMT -6 akent said:

That's awesome flying BT!!
I'm really impressed to hear about how well the CP2 works. I've read about Mckrackin and a couple of others rave about them. It's an amazing piece of equipment.

Once I get the vibes out of my ES600, I may get one of those for it. I would like to build up a camera platform.

Take care,
Kent

Its as much psychological as anything. I would say 60% CP2 40% security blanket.

BTW, I took the time to change to the Align CF frame this time. I was going to have to split the frame some to get the servos out and I noticed the main shaft bearings didn't line up anymore so I decided to break out the good stuff. I'm not sure what will be left of the EXI when I patch everything back together. I'm in bad need of one of those CNC heads and tails from Xheli, though.

The crash took out two of my servos. One broke the little plastic pin off that one of the gears rides on. The other got smoking hot when I tried to use it after a new gear set. Time for metal.

[BTCat]

WOW! I think I have a different heli! It was 11:00 when I put the final touches on it, so all I did was hover in the front yard a little, but it sounds like a completely different machine.

There were only two things that I did to make any differance. I used the Align CF frame I had stashed and I cleaned and soaked all my bearings in synthetic oil. The head is still the patch together CopterX/EXI from my last crash.

I'll give it a good run tomorrow. I just can't believe how much more smoothly it spun up.

I ended up with very little damage to the main rotor, except linkage. Two of three servos were toast. I had one spare and I had enough parts to combine for a repair on the other one. The feathering shaft was fine. The tail shaft was bent.

I like rebuilding these things. I rerouted everything and cleaned the wiring up some.

Tomorrow's the real test...

[BTCat]

Here are some pics from before and after. Crashed Because the Tail Boom Twisted in the Mount:



Not a big parts list. The worst was the two servos. I was able to put together the scraps to make one good one. Replaced the other with an HS65MG The Frame was already a little worse for the wear, but this time it had a slight zigzag at the top and bottom main shaft bearings:



A Good Excuse To Use This. Got it on sale for $50 a few months ago:

[BTCat]

I put all my electronics vertically in the frame. Originally I turned the RX out and routed the wires outside the frame. For a cleaner (but much tighter) look, I turned it inward and routed as much of the TX/ESC/Copilot 2 wiring within the frame.

[BTCat]

Finished and Ready to Fly. The only remaining EXI part is very clear in the first pic. A big bug was on the wall when I took the second pic:

[Solitaire]

...and just a hint of orange tailblade. ;D

Gotta say though, you have the cutest bugs down there. Big, but cute.

[BTCat]

Sept 7, 2009 13:00:49 GMT -6 Solitaire said:

...and just a hint of orange tailblade. ;D

Gotta say though, you have the cutest bugs down there. Big, but cute.

Cute, but mean ;D

Sol, recognize the white blades? Those are the fiber ones you sent. Where did you get them? The CG was exactly the same on both and the balance was perfect!

I flew 4 packs this morning, but I have a case of dumbthumb, so I didn't push it too far.

[Solitaire]

Those blades are the ones Kent put us onto. HeliDirect $6.30/set, although they've been out of them for a while.

Probably the best deal around on decent FG blades.
www.helidirect.com/325mm-pro-frp-fiberglass-main-blade-trex450hdx450-p-10348.hdx